This invention relates to a self-regulating pressure source, and more particularly to such a pressure source adapted to power soft actuators fabricated from elastomer films having embedded fluidic channels.
Pressure is a convenient actuation source for soft actuators as it induces local deformation in a soft substrate [1], giving a large actuation range limited only by the mechanical strength of the material. In general, using direct mechanical energy in the form of pressure bypasses the need for electrical energy and its constraints. On the other hand, an important limitation on fluidic actuation is the necessity of a pressure source [2]. The numbers in the brackets refer to the references included herewith. The contents of all of these references are incorporated herein by reference in their entirety.
Hydrogen peroxide has been used previously as a monopropellant [3] and recently in robotics applications [4, 5, 6]. A recent work utilized H2O2 to build a self-powered microfluidic lab-on-a-chip system [7]. Using H2O2 to generate pressure has the benefit of using no conventional power source for operation. Hydrogen peroxide naturally decomposes into oxygen and water with no harmful byproducts at a slow rate. This reaction speeds up in the presence of a catalyst [8]. Once this exothermic reaction starts, it continues until all of the H2O2 is consumed or the catalyst is removed. In previous works, relief valves were utilized to periodically vent the gas to keep the pressure build-up under control [4].
There is currently a need to develop robotic devices that rely upon new high-performance soft actuators. Compliance allows conformation, which is desirable for adaptability in the device's negotiation with the world. A low minimum stiffness ensures safety in human interaction [9]. Many application areas will benefit from advances in practical soft actuation mechanisms including medical robotics, artificial muscles, and human interaction devices such as tactile or haptic interfaces. A robust pressure source is therefore desirable to advance soft actuator technology.